[ DISEASES OF CITRUS TREES 



low prices, but it does not interfere in any way with 

 the keeping quality and aroma of the fruit, although 

 it may cause some injury to the tree by depriving 

 the green tissues of the influence of air and the direct 

 rays of the sun. In late spring the fungus shrivels and 

 separates in crusts, and the leaf if not past its age, 

 continues to keep its hold on the twig green and 

 apparently healthy as before infection. Spraying with 

 Bordeaux mixture or any other approved fungicide may 

 be attemped by way of prevention. 



Another well-known fungus having a history similar 

 to the preceding is the Meliola Citri Sacc. or Apiosporum 

 Citri, the maldi Cenere of Italian orange growers. Like 

 the preceding it lives on the leaves, twigs and fruits 

 of Citrus trees, covering the same with ash-coloured 

 crusts, which turn darker with age. On removing these 

 crusts with the finger, the leaf is found to retain its 

 green colour, and does not appear to have suffered 

 much from the thick crust of mycelium which covered 

 it. It is rarely seen in Citrus groves in these Islands, 

 although very common all over Italy. The conditions 

 which favour the growth of Meliola Citri and of Meliola 

 Penzigi are identical, the first being possibly a mere 

 variety of the second, and the same' preventive treatment 

 is applicable to both. But the best way to prevent 

 the attacks of Meliola is to combat the scale-insects, 

 and to rear the trees on tall trunks in order to favour 

 the circulation of air all over the grove. 



Fomes obliquus, Cooke, (Pohporusobliquus, Pers.) is a 

 true parasite often found on the trunk and the undersurface 

 of large branches of Citrus trees. Its mycelium lives at 

 first at the expense of the cambium, and then enters 

 the wood killing it, feeding upon it, and transforming 

 it into a friable brown mass. In due time the sporocarp 

 buds out as a round or oval flat mass of a chocolate 

 brown colour, having its surface covered by minute 

 holes or pores, set thickly and obliquely, from which 



